The purpose of this project is to determine the causes of diabetic retinopathy and ultimately the optimal methods to prevent it. All participants in the Pima Indian Longitudinal Study of Diabetes were invited to have their retinas digitally photographed. Batches of photographs are periodically sent for systematic reading for research purposes. The results of these systematic readings become the outcomes for analyses of predictors of diabetic retinopathy. Analysis of data from this project has recently suggested that an area on chromosome 1 may harbor a gene or genes conferring susceptibility to diabetic retinopathy. During FY2009 we had an additional 4255 retinal photographs read. These newly read retinal photographs were taken from 1989 through 2007, and they represent a large collection of outcomes data that we have begun during FY 2010 to analyze in the search for predictors of this particular complication of diabetes. Since November 2010 we have photographed the retinas of diabetic participants in the Molecular and Clinical Profile of Diabetes Mellitus and its Complications study. The retinal imaging and clinical interpretation are performed by the Joslin Vision Network at their Phoenix Indian Medical Center site. Through FY 2011 we expect to collect retinal images from more than 50 participants.